The iPad is changing the way student's conduct their studies. With the iPad you can carry around as many books as you need, without any increase in the weight of your bag. The Amazon Kindle store and Apple's iBook store both stock thousands of books. But these are just digital versions of paper books. With the hardware in the iPad the humble book is suddenly capable of so much more. This is why Apple have created a new standard for digital Textbooks, and it's built into iBooks 2, which is free on the App Store:

In these new text books you there are embedded 3D images, embedded photo gallery's and video content. They also give feedback on the multiple choice questions you get at the end of a chapter. For a preview of these features click here.
To create text books for the iPad Apple have created a new software package: iBooks Author.